jaeger agent cost too much cpu

[zdyj3170101136]

I find that jaeger agent costed too much cpu.

The jaeger agent flamegraph：

The mainly cost is from:
1, unmarshal from []byte to thrift struct
2, tran from thrift struct to domain struct
3, send over grpc(marshal domain struct to proto)
4, gc cost

So I want to reImplement jaeger-agent in my company:
1, receive []byte from udp
2, directly send []byte to jaeger-collector over websocket

And the jaeger-collector:
1, receive []byte from websocket conn
2, tran from thrift struct to domain struct

The advantage of my situation:
Save the domain struct marshal and unmarshal cpu cost.

I had try using different protocol send from client to jaeger agent (udp, unixgram, unixhttp)
in https://github.com/zdyj3170101136/exp-jaegerproto：

udp                          10000000 spans| 38.7 cpusec| 37.6 wallsec| 2582.6 batches/cpusec|  2662.2 batches/wallsec|  3.9 cpuμs/span
unixgram                     10000000 spans| 38.4 cpusec| 37.4 wallsec| 2604.2 batches/cpusec|  2673.5 batches/wallsec|  3.8 cpuμs/span
unixhttp                     10000000 spans| 36.9 cpusec| 36.0 wallsec| 2710.0 batches/cpusec|  2775.1 batches/wallsec|  3.7 cpuμs/span

Different protocol do not have too much performance different.